Very good play by Abdusattorov.
19. g4f3  19... e8c8 Abdusattorov plays all the best moves. As a matter of fact, he will continue doing so until the end of the game. 20. c3d5 Van Foreest had probably already foreseen this move before playing 17.b5. 20... e6d5  21. c4d5 